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Magnetoreception

Overview

Magnetoreception

  • sense that allows organisms to detect magnetic fields
  • accepted in bacteria, arthropods, mollusks, and members of all major taxonomic groups of vertebrates
  • chemical magnetoreception (Cryptochromes)(1), magnetite-based magnetoreception(2), and electromagnetic induction(3)
  • focus electromagnetic induction in Elasmobranches (sharks, skates, and rays)

Ampullae of Lorenzini

Electromagnetic induction(2)

Magnetite-based(1)

Examples of the three kinds of magnetoreception:

Cryptochrome(3)

History

  • The first studies of electrosensing capability in aquatic animals -Parker and van Heusen 1917, blinded catfish and rods
  • Lissmann 1951- electric discharges during prey capture
  • Dijkgraaf & Kalmijn in 1935-replicated Parker and van Heusen but with sharks and a rusty steel wire
  • Years of research testing the sensing capability but did not know what part was reasponsible for this ability
  • Stefeano Lorenzini-Ampullae of Lorenzini
  • R.W. Murray 1960- found it was these organs responsible for field detection
  • The Ampullae of Lorenzini became known as Electroreceptors after his research-sensing organs Ef

Electroreption

Ampullae of Lorenzini

  • The Ampullae of Lorenzini consists of many ampulla that are each consisted of a jelly-filled tube that opens to the surface by a pore in the skin (1). These ampullae pores are very visible as dark spots on the skin of the animals(2).
  • The jelly inside the tube is highly conductive, which allows the electrical potential at the pore opening to be transferred to the ampulla at the base of the tube. Voltage differences across the membrane lining each ampulla then cause nerves to be activated, sending signals to the brain (3).

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3

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Purpose

  • prey location and capture
  • agar chamber Kalmijn, 1971 (1)
  • magnetic field detection
  • Meyer, Holland, and Papastamatiou-artificial magnetic field, food reward

Main Purpose of Electroreceptors

1

Electromagnetic Induction

  • Electromagnetic induction is the process where an electromotive force is produced across an electrical conductor by varying the magnetic field or magnetic flux
  • Faraday’s equation for electromagnetic induction.
  • Faraday’s equation for electromagnetic induction states that the induced emf (electromotive force) is proportional to the rate of change of the magnetic flux.

Electromagnetic induction

wire problem

Faraday's law shark version

Faraday’s Law Shark Version

  • Any moving conductor induces an electric field when a magnetic field is present. The moving water in the ocean serves as the conductor and the Earth's magnetic field is present so an electric field will be induced around the object swimming through the field, in this case, the shark (1).
  • Tiny differences in the Earth’s magnetic field at different locations results in tiny differences in the induced electric field which can be detected by the shark’s electroreceptors, especially as the head region moves back and forth during swimming (Johnsen, Lohmann, 2000). The sharks Ampullae of Lorenzini detects this induced emf when swimming through the field (Stroud, Rice, Hansen, DeSanti, 2018).

1

Applications

  • Shark deterrent Sharkbanz from SharkDefense Technologies LLC
  • Perdue Quantum material with capability to detect electric fields
  • Caltech bridge of discovering humans magnetoreception ability

Applications

2

1

3

Sharkdefense Technologies llc.

  • Dr. Eric and Jean Stroud have used findings on shark’s ability to detect magnetic fields through electromagnetic induction and created SharkDefense Technologies LLC.
  • Leading researchers of chemical, electrochemical, and magnetic shark repellents.
  • Goals: create shark bycatch reduction devices, create shark deterrents for rescue operations, aquaculture and alternatives to shark netting
  • Sharkbandz- They found that the flux per unit area of certain permanent magnets, particularly Neodymium-Iron-Boride and Barium-Ferrite magnets, corresponds closely with the detection range of the Ampullae of Lorenzini. If the magnet has the correct specifications, they use it to overstimulate the sharks Ampullae of Lorenzini, deterring the sharks away from the area. Causes them uncomfort.

Sharkbanz

  • Dr. Narayanan at Purdue University created a quantum material (samarium nickelate) sensor that can detect electric fields as small as orders of millivolts from studying research done on sharks ability to detect electrical fields (Schwanz, Zhang, Narayanan, 2017).

Perdue Quantum material

Quantum material that detects E fields

Humans magnetoreception ability

Caltech

  • Geoscientist Joseph Kirschvink, and neuroscientist Shin Shimojo at Caltech University partnered with neuroengineer Ayu Matani at the University of Tokyo are studying humans ability to detect changes in the Earth’s magnetic field.
  • Built an isolated radiofrequency-shielded chamber and shifted the magnetic field while studying participants’ brain waves in response to the shift via 64 electrodes on their heads.
  • When the brain is perceiving stimulus its alpha wave level drops and picks back up to baseline when the stimulus is removed. They found that seconds after the applied magnetic stimulation participants’ alpha levels dropped dramatically and within 60% in several hundreds of milliseconds, then back to baseline seconds after the stimulus ended.
  • They conclude this could show how our nomadic ancestors navigated the earth or play a big role in our orientation and balance.

References

citations

  • DIJKGRAAF, S. & KALMIJN, A. J. (1962). Verhaltungsversuche zur Funktion der Lorenzinischen Ampul- len. Naturwissenschaften 49, 400
  • Johnsen S, Lohmann KJ. The physics and neurobiology of magnetoreception. Nature Reviews Neuroscience. 2005;6(9):703–712. [PubMed] [Google Scholar]
  • KALMIJN, A.J. 1971. The electric sense of sharks and rays.J. Exp. Biol. 55:371.
  • LISSMANN, H. W. (1951). Continuous electrical signals from the tail of a fish, Gymnarchus niloticus Cuv. Nature, Lond. 167, 201—2
  • Matani, A., Shimojo, S., Kirschvink, J. Transduction of the Geomagnetic Field as Evidenced from Alpha-band Activity in the Human Brain. eneuro, 2019; ENEURO.0483-18.2019 DOI: 10.1523/ENEURO.0483-18.2019
  • Meyer, C. G., Holland, K. N., & Papastamatiou, Y. P. (2005). Sharks can detect changes in the geomagnetic field. Journal of the Royal Society, Interface, 2(2), 129–130. https://doi.org/10.1098/rsif.2004.0021
  • MURRAY, R. W. (i960). The response of the ampullae of Lorenzini of elasmobranchs to mechanical stimulation. J. Exp. Biol. 37, 417-24.
  • PARKER, G. H. & VAN HEUSEN, A. P. (1917). The responses of the catfish, Amiurus nebulosus, to metallic and non-metallic rods. Am. jf. Physiol. 44, 405-420.
  • Schwanz, D., Zhang, Z., Narayanan, B. et al. Perovskite nickelates as electric-field sensors in salt water. Nature 553, 68–72 (2018). https://doi.org/10.1038/nature25008
  • Stroud, E., Rice, P., Hansen, J., DeSanti, B. Sharkbanz MAGNETIC TECHNOLOGY RESEARCH & CLAIMS, 2018; https://cdn.shopify.com/s/files/1/1826/7677/files/Sharkbanz-Technology-Research-Claims-2018.pdf?11136348900500449280

Figure citations

  • (1) Wikipedia contributors. (2020, July 4). Magnetoreception. In Wikipedia, The Free Encyclopedia. Retrieved 03:25, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Magnetoreception&oldid=965885292

  • (2) Wikipedia contributors. (2020, June 6). Electroreception. In Wikipedia, The Free Encyclopedia. Retrieved 03:50, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Electroreception&oldid=961138798

  • (3) Wikipedia contributors. (2020, July 11). Ampullae of Lorenzini. In Wikipedia, The Free Encyclopedia. Retrieved 03:53, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Ampullae_of_Lorenzini&oldid=967174312

  • (4) Wikipedia contributors. (2020, July 11). Electromagnetic induction. In Wikipedia, The Free Encyclopedia. Retrieved 03:57, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Electromagnetic_induction&oldid=967204514

  • (5) Wikipedia contributors. (2020, May 27). Faraday's law of induction. In Wikipedia, The Free Encyclopedia. Retrieved 03:58, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Faraday%27s_law_of_induction&oldid=959079316

  • (6) Wikipedia contributors. (2020, July 18). Lenz's law. In Wikipedia, The Free Encyclopedia. Retrieved 03:59, July 26, 2020, from https://en.wikipedia.org/w/index.php?title=Lenz%27s_law&oldid=968314294

  • https://arundivysharks.weebly.com/sensitivity.html
  • https://physicstoday.scitation.org/doi/10.1063/1.2897947
  • http://1.bp.blogspot.com/-iDgqesy1GGg/UgBaqRIq_gI/AAAAAAAABq0/TdqY88LNhZA/s1600/shark-cartoon-201.jpg
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